Vape kit help

I stopped smoking 6 years ago using an ecig but have stupidly restarted. Want to get an ecig asap so I can stop but no idea where to start. Things have moved on a lot and I don't know anything about the new kits. What is sub ohm and mouth to lung? I would be using fairly low nicotine liquid and wanting to move to nicotine free quite quickly. Not looking to spend a fortune on a kit (prefer less than £50). Can anyone help?

Vaping is more likely to help you stop smoking if you don't rush it with reducing nicotine. Nicotine really isn't very harmful without tobacco, so start with whatever works and don't be too ambitious!

I've recently bought a little Aspire Pockex as a back up vape and it's very good, fairly cheap and works with standard liquids. My main vape kit is an eLeaf iStick 20/30w battery and an Aspire Triton tank, still not very expensive but I've been off the fags over 3 years now so it's working well.

Mouth to lung is like smoking, you draw on the fag/vape into your mouth and then inhale. Sub ohm vaping you draw on like you would of you were using a medical inhaler straight into your lungs, it makes big clouds but also uses a lot of juice, it's often more a hobby than a smoking replacement.

Right, it looks like the E Smart tanks/clearomisers are treated as disposable these days (you used to be able to just buy the all in one base/atomiser and not have to replace the whole thing) but I've found some here for 5 for £10 which is ok. MyEPack have the starter kits E Smarts for £10.

Further googling suggests the E Smart has been discontinued so I'd probably avoid. I'm going to return to my Aspire Pockex suggestion which is chunkier but easy, lovely and shouldn't be a problem for spares.